Self-propelled screening apparatus

ABSTRACT

A self-propelled screening apparatus ( 1 ) having a chassis ( 11 ); a pair of endless tracks ( 12 ) supporting the chassis ( 11 ); a superstructure ( 13 ) rotatably mounted on the chassis ( 11 ); a prime mover provided in or on the superstructure ( 13 ) and arranged to provide motive power to operate the endless tracks ( 12 ) and where the prime mover is rotatable with the superstructure ( 13 ); and a screen box ( 16 ) mounted on the superstructure ( 13 ), also for rotation therewith. The screen box ( 16 ) has an input ( 17 ) for receiving a supply of bulk material, at least one screen deck for screening the bulk material, and an output for discharging screened material. The prime mover and the screen box ( 16 ) are arranged on opposite sides of the rotational axis of the superstructure ( 13 ), to provide a stable weight distribution.

This invention relates to a self-propelled screening apparatus which isoperative to screen a supply of bulk material into at least one sizerange of screened material, and to discharge the screened material to arequired deposition zone.

Screening apparatus or plants are used to separate out a supply of bulkmaterial into one or more size ranges of screened material, andtypically may be used in quarry locations in order to separate crushedstone into different size ranges of e.g. ballast, sand, gravel and thelike. They may also be used in land or site clearance work, when thebulk material may be rubble, broken concrete, tree roots and soil.

Some screening apparatus are very large static installations, whenintended for long term use at a particular site. Other apparatus aredesigned to be transportable from site to site, either via a low loader,or as a towed vehicle, and such apparatus therefore has to be designedto be convertible between a transport mode and an operating (screening)mode.

Still further screening apparatus are self-propelled, and which aretherefore required to be easily manoeuvrable, for the purposes ofloading the apparatus with bulk material at any particular location, andfor discharging screened material at a required deposition zone.

The present invention is concerned with a self-propelled screeningapparatus, and seeks to provide, by simple means, an apparatus which isvery easily manoeuvrable, and yet also is stable, despite the fact thatbulk material is being handled, and the necessary screen or screens tohandle the bulk material provide substantial mass, and also generatesubstantial inertia.

According to one aspect of the invention there is provided aself-propelled screening apparatus which comprises:

a chassis;

a pair of endless tracks supporting the chassis;

a superstructure rotatably mounted on the chassis;

a prime mover provided in or on the superstructure and arranged toprovide motive power to operate the endless tracks, said prime moverbeing rotatable with the superstructure; and

a screen box mounted on the superstructure, also for rotation therewith,said screen box having an input for receiving a supply of bulk material,at least one screen deck for screening the bulk material, and an outputfor discharging screened material;

in which the prime mover and the screen box are arranged on oppositesides of the rotational axis of the superstructure, to provide a stableweight distribution.

According to a second aspect of the invention there is provided aself-propelled screening apparatus which comprises:

a chassis;

a pair of endless tracks supporting the chassis;

a superstructure rotatably mounted on the chassis via a slewing ring;and

a screen box mounted on the superstructure for rotation therewith, saidscreen box having an input for receiving a supply of bulk material, atleast one screen deck for screening the bulk material, and an output fordischarging screened material.

The invention therefore provides an easily manoeuvrable apparatus viathe endless tracks, and also by means of the rotational adjustment ofthe screen box relative to the chassis to suit loading and/or screeningrequirements.

The superstructure may comprise a housing or canopy in which an enginemay be mounted, and which serves as a source of power to operate theendless tracks, and preferably also any driven components of the screenbox e.g. a vibrating mechanism. The engine may be an internal combustionengine, or any suitable power source e.g. a hydraulic pump driven by anysuitable means.

The screen box may have more than one screen deck, and may have aloading chute at an inboard end (with respect to the rotational axis)and oversized material i.e. material which is too large to passdownwardly through the screening apertures, may pass directly over thetop of the upper screen deck to be discharged via an outboard end of thescreen box.

If it is required to provide a facility whereby the discharge from thescreen box may be adjustable inwardly or outwardly of the rotationalaxis of the superstructure on which the screen box is mounted i.e. tomove the discharge point nearer to, or further from the apparatus, thescreen box may be mounted on, or incorporate a telescopically adjustableframe.

The weight distribution of the apparatus is such that the weight of thescreen box (and any material being handled) is balanced by othercomponents of the apparatus on the superstructure e.g. the prime mover.

The screen box may carry out screening operations while the apparatus isstatic, or on the move if required. Also, via the slewing ring, thescreen box can take up any required rotational position through 360°about the rotational axis as may be required, and therefore may includedischarge of screened material forwardly, or rearwardly of the directionof travel, or transversely thereof e.g. at 90°.

To further provide for flexibility in operation, by enabling additionalpositional adjustment of the discharge of screened material, the screenbox may be adjustably mounted on the superstructure.

The apparatus may have a driver's cab, and from which an operator cancontrol the movement of the apparatus and/or screening operations.

Alternatively, the apparatus may be arranged to be capable of beingoperated by remote control, e.g. an infra-red control or a radiocontrolled system, and which might be provided, for example, in theoperating cab of a loading vehicle which is being used to load theapparatus with bulk material.

A preferred embodiment of self-propelled screening apparatus accordingto the invention will now be described in detail, by way of exampleonly, with reference to the accompanying drawing, in which:

FIG. 1 is a side view of a self-propelled screening apparatus accordingto the invention, and showing a screen box mounted on one end thereof,and with respect to the longitudinal axis of the apparatus; and

FIG. 2 is an end view, showing the screen box rotated through 90° to alateral discharge position.

Referring now to the drawing, a self-propelled screening apparatusaccording to the invention is designated generally by reference 10 andwhich comprises a chassis 11, and a pair of endless tracks 12 whichsupport the chassis 11 and which are driven by any suitable prime mover(not shown) in order to propel the apparatus over the ground. Evidently,by providing endless tracks, selective operation of one or more of thetracks provides easy manoeuvrability of the apparatus, and especially inview of the relatively short length of the tracks, and also therelatively short length of the superstructure mounted on the chassis 11,and as described below.

A superstructure 13 is rotatably mounted on the chassis 11, via aslewing ring 14, whereby the superstructure 13 can be rotated through360° about a substantially vertical axis passing through the centre ofthe slewing ring.

The superstructure 13 includes an engine housing or canopy 15 in which aprime mover can be mounted, and which may be an internal combustionengine, or any other suitable power source e.g. a driven hydraulic pump.

The prime mover provides drive power to operate the endless tracks 12,and also serves to provide drive input (if required) to a screen box 16which is mounted on the superstructure 13. The screen box 16 istherefore rotatable with the superstructure 13, and can take up an“in-line” position as shown in FIG. 1, or a transversely extendingdischarge position shown in FIG. 2. Other angular adjustments about therotational axis can be taken up, according to a required deposition zonefor screened material.

If required, additional positional adjustment of the discharge ofscreened material may be obtained by providing an adjustable mounting ofthe screen box 16 on the superstructure 13.

Although not shown in detail, the screenbox 16 may be pivotally adjustedabout pivot axis 16 a to alter the deposition point for screenedmaterial relative to the superstructure 13, i.e. the screenbox 16 may beindependently adjustable relative to the superstructure 13, and whichalso is adjustable relative to chassis 11 and endless tracks 12.

In a preferred arrangement, the screenbox 16 may be adjustable in eitherdirection through up to 90° from a datum position relative to thesuperstructure 13.

The screen box 16 has an input in the form of loading chute 17, whichreceives a supply of bulk material, and at least one screen deck forscreening the bulk material, and an output for discharging the screenedmaterial. Oversized material i.e. material which is too large to passdownwardly through the screening apertures, may pass directly over theupper screen deck, to be discharged from the outboard end of the screenbox 16.

As can be seen in FIG. 1, the screen box 16 is located at one end of theapparatus i.e. is spaced from the rotational axis provided by thestewing ring 14, and therefore to counterbalance this weight, the primemover is mounted within the housing 15 at the opposite side of therotational axis. This provides a stable arrangement, during operation.

The prime mover, which is mounted in the housing 15, serves as a sourceof power to operate the endless track 12, and also drive any componentsof the screen box e.g. a vibrating mechanism, if required.

The screen box 16 may have more than one screen deck, if it is requiredto screen the bulk material into more than one screened size range.

In order to provide a facility whereby discharge from the screen box maybe adjusted inwardly or outwardly of the rotational axis of thesuperstructure (and therefore also of the screen box), the screen boxmay be mounted on, or incorporate a telescopically adjustable frame, asshown by reference 18.

The apparatus 10 may include a driver's cab (not shown), from which anoperator can control the movement of the apparatus and operation of thescreen. Alternatively, the apparatus 10 may be arranged to be operatedby remote control e.g. an infra-red or radio control system, or via anumbilical. The remote control conveniently can be exercised by thedriver of another vehicle working in conjunction with the screeningapparatus e.g. the operator of a loading vehicle delivering supplies ofbulk material to the screening apparatus.

The preferred embodiment of the invention therefore provides a simple,but easily manoeuvrable apparatus which can carry out screeningoperations, and whose position can be adjusted to suit loadingrequirements and/or discharge requirements of the screened material.There is no need to provide an under-conveyor to work with the screenbox, to discharge the screened material. Furthermore, the apparatus canwork in any angular position of adjustment about the axis of the slewingring. The weight distribution of the components mounted on thesuperstructure is such as to provide a stable operating system.

1. A self-propelled screening apparatus which comprises: a chassis; a pair of endless tracks supporting the chassis; a prime mover provided in or on the superstructure and arranged to provide motive power to operate the endless tracks, said prime mover being rotatable with the superstructure; and a screen box mounted on this superstructure, also for rotation therewith, said screen box having an input for receiving a supply of bulk material, at least one screen deck for screening the bulk material, and an output for discharging screened material; in which the prime mover and the screen box are arranged on opposite sides of the rotational axis of the superstructure, to provide a stable weight distribution.
 2. A self-propelled screening apparatus which comprises: a chassis; a pair of endless tracks supporting the chassis; a superstructure rotatably mounted on the chassis via a slewing ring; and a screen box mounted on the superstructure for rotation therewith, said screen box having an input for receiving a supply of bulk material, at least one screen deck for screening the bulk material, and an output for discharging screened material.
 3. Apparatus according to claim 1, in which the superstructure comprises a housing or canopy in which an engine is mounted, and which serves as a source of power to operate the endless tracks.
 4. Apparatus according to claim 3, in which the engine is arranged to drive driven components of the screen box.
 5. Apparatus according to claim 1, in which the screen box has more than one screen deck, and has a loading chute at an inboard end, and an opposite discharge end over which oversized material can be discharged.
 6. Apparatus according to claim 1, in which the screen box is adjustable inwardly or outwardly of the rotational axis of the superstructure, to move the discharge point relative to the apparatus.
 7. Apparatus according to claim 6, in which the screen box is mounted on, or incorporates a telescopically adjustable frame.
 8. Apparatus according to claim 1, and including a driver's cab from which an operator can control the movement of the apparatus and/or screening operation.
 9. Apparatus according to claim 1, in which the apparatus is arranged to be capable of being operated by remote control.
 10. Apparatus according to claim 1, in which the screenbox is independently adjustably relative to the superstructure.
 11. Apparatus according to claim 1, in which the screenbox is pivotable through up to 90 degrees in either direction from a datum position relative to the superstructure.
 12. Apparatus according to claim 2, in which the superstructure comprises a housing or canopy in which an engine is mounted, and which serves as a source of power to operate the endless tracks.
 13. Apparatus according to claim 12, in which the engine is arranged to drive driven components of the screen box.
 14. Apparatus according to claim 2, in which the screen box has more than one screen deck, and has a loading chute at an inboard end, and an opposite discharge end over which oversized material can be discharged.
 15. Apparatus according to claim 2, in which the screen box is adjustable inwardly or outwardly of the rotational axis of the superstructure, to move the discharge point relative to the apparatus.
 16. Apparatus according to claim 15, in which the screen box is mounted on, or incorporates a telescopically adjustable frame.
 17. Apparatus according to claim 2, and including a driver's cab from which an operator can control the movement of the apparatus and/or screening operation.
 18. Apparatus according to claim 2, in which the apparatus is arranged to be capable of being operated by remote control.
 19. Apparatus according to claim 2, in which the screenbox is independently adjustably relative to the superstructure.
 20. Apparatus according to claim 2, in which the screenbox is pivotable through up to 90 degrees in either direction from a datum position relative to the superstructure. 